lvm dies while snapshotting

[Jamie Strandboge]

While preparing security updates using sbuild and lvm snapshots, I get hard lockups. I use ext4 in my snapshots with root on software raid 1 (also ext4).

Reproducer:
1) schroot -c dapper -u root
2) schroot -c dapper -u root
3) in each chroot 'apt-get build-dep klamav'
4) wait awhile for each to download the debs and start unpacking
5) ctrl+c in each then 'exit' in each. one will exit, the other will churn
6) in the one that exited, do 'schroot -c dapper -u root' while the other is still churning

At this point I see '05lvm killed' (presumably from /etc/schroot/setup.d) and everything hard locks. I don't have an oops or traceback in dmesg. This may be related to bug #543617 (which also affects me).

$ uname -a
Linux severus 2.6.32-18-generic #27-Ubuntu SMP Fri Mar 26 21:13:44 UTC 2010 x86_64 GNU/Linux

$ cat /proc/version_signature
Ubuntu 2.6.32-18.27-generic 2.6.32.10+drm33.1

[Andy Whitcroft (apw)]

@Jamie as the bug you link to is now closed Fix Released you should be able to confirm you conjecture that this is or is not the same issue. Let us know.

[Jamie Strandboge (jdstrand)]

I just tested this, and I could not get it to crash with the latest kernel. Kees and I thought that using lvm aggravated the issue in #543617, and the sync fix in there seems to have fixed it here. If I come across this again, I'll reopen, but am duping for now.